Re: [PATCH -tip 1/4] [BUGFIX] perf tools: Initialize dso->node member in dso__new

[Arnaldo Carvalho de Melo <acme@redhat.com>]

Em Wed, Apr 21, 2010 at 03:56:16PM -0400, Masami Hiramatsu escreveu:
> If dso->node member is not initilized, it causes a segmentation
> fault when adding to other lists. It should be initilized in
> dso__new().
> 
> Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
> Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: Mike Galbraith <efault@gmx.de>
> Cc: Frederic Weisbecker <fweisbec@gmail.com>
> Cc: Ingo Molnar <mingo@elte.hu>
> ---
> 
>  tools/perf/util/symbol.c |    1 +
>  1 files changed, 1 insertions(+), 0 deletions(-)
> 
> diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
> index e782e7d..e77c33a 100644
> --- a/tools/perf/util/symbol.c
> +++ b/tools/perf/util/symbol.c
> @@ -189,6 +189,7 @@ struct dso *dso__new(const char *name)
>  		self->sorted_by_name = 0;
>  		self->has_build_id = 0;
>  		self->kernel = DSO_TYPE_USER;
> +		INIT_LIST_HEAD(&self->node);
>  	}
>  
>  	return self;

Trying to understand how this would be a problem, as:

static inline void __list_add(struct list_head *new,
                              struct list_head *prev,
                              struct list_head *next)
{
        next->prev = new;
        new->next = next;
        new->prev = prev;
        prev->next = new;
}

This is not a list head, just a node.

Looking at other messages where you described the problem to try to
understand why this would help.

- Arnaldo